Wall-board



J. E. DALGLISH.

WALL BOARD. APPLICATION FILED SEPT. I5, I92o.

Patented Aug. 2', 1921.

A TT ORNE Yj ,UNITED STATES PATENT JOHN EASTON DALGLISH, OF

` WALL-:30113311 ATo all whom it may concern."

Be it known that'l, JOHN Ev.- DALGLISH, a, citizen of the United States, residingat Somerville, in ythe county of Middlesex and State of Massachusetts, have invented new and useful Improvements/in Wall-Boards, of which the following is a specification.

rlhis invention relates to facings for buildand more particularly to devices of this kind in :the form of a slab or tile. The invention has for its object to provide a very strong and durable as well as a fire proof wall board, and one which has a smooth surface and which will not warp.

5 The invention also has for its object to provide a wall board which is very simple cation.

and inexpensive,and which can be manufactured at thebuildin site.A

Other objects and vantages of the in. vention will be pointed-out in the detailed description appearing hereinafter, and in order that the same may be better under stood, reference is had t0 the accompanying drawing forming a part of this specifi- In the drawing,

Figure 1 is a plan view of the article, and Figs. 2 and 3 are cross sectionslon the lines 2-,2 and 3 3, respectively of F'ig. 1 Referring specifically to the drawing, the `wallboard is 'composed of a rectangular slab 5 of plastic material in which are embedded wooden strips 6. The material of which the slab is made is a mixture of plaster of Paris, saw dust and marble dust to which a ysuitable quantity of water isadded to produce a plastic mass which is molded "and allowed to set until it assumes a hard mass. The plastic composition is poured lnto the mold, a sufficient quantity being poured to I produce a thin slab. A sheet of burlap 7 or other suitable rough reticulated binder niaterial is then placed on top ofthe slab and pressed down into the composition, after which the wooden strips 6 are placed on top of the burlap sheet, which latter is now pulled over the wooden strips along the sides of the slab, and short pieces of burlap 8 are spread Specification of Letters Patent.

oFFlcs.

soMEnvrIl-LE, MAssAcHUsE'rrs Patented Allg'. 2, i921. 15, `1920. serial No. 410,356. y

smooth. After the plastic mass has hardened the top is polished to form the face of the slab. The burlap embedded in the slabl act/s as a binder to hold the plastic composition ing walls generally known as wall boards, together, and the wooden strips serve to reinv force the slab, and they are also employed for nailing purposes. It will be noted that the slab is rabbeted at its edges so that when a number of slabs are assembled to produce a wall facing, they may be interlocked and a smooth joint between the slabs is made possible. It will be understood, however,

that any other type .of joint may be employed. The wooden strips are positioned to lie in the rabbeted portions-of the slab,

and hence the heads of the nails driven therethrough are completely concealed. f

A slab constructed as hereinbefore dealso very strong and durable. The slabs can be nailed directly to the studding, and by .pplying some of the same plastic composi'- g t1on over the joints, and troweling the same smooth, a perfectly smooth w'all is obtained, l-all the joints beingcovered and thus con- 'lcealed The slabs may also be given an ornamental face and used for ceilings, and

scribed is lire-proof and water-proof and no lathing or grounds are needed. A'further advantage of a slab constructed as hereinbefore'described is its cheapness, and the fact that it can be manufactured directly at the building site, thus saving transportation expenses.

I claim: 4

A building unit composed 0f a slab of plastic material having rabbeted edges,

wooden strips embedded in the body of the slaband also in the rabbeted edgewportions thereof, 'said edge strips running in the direction of the length of the edges of the slab, and a reticulated binder sheet around the strips, said sheet being also embedded in the slab.

In testimony whereof I aliix m si attire.'

JOHN EASTON DA G ISH. 

